Chronic pain is a major source of human suffering and a major economic problem in American society. Because the problem has long gone unrecognized, there has been little research on which to base improvements in pain patient management. We propose to carry out six interrelated research projects involving varying disciplines that will shed light on the mechanisms of pain, the development of pain chronicity, the clinical manifestations of chronic pain, and the treatment of chronic pain. In order to accomplish this we will establish a multidisciplinary network of scientific interchange, collaboration, and resource sharing that enhances and expedites the work done under each of the individual projects. Interchange among project leaders will be both informal and formal including monthly project seminars and semi-annual consultation visits by outside scientists. This research program will take place within the developing University of Washington School of Medicine Pain Center which is directed by the Co-Principal Investigator, and it will be closely coordinated with the activities of the Clinical Pain Service which has as its principal mission the management of chronic pain.